Postoperative sleep disruptions: a potential catalyst of acute pain?

Despite the substantial advances in the understanding of pain mechanisms and management, postoperative pain relief remains an important health care issue. Surgical patients also frequently report postoperative sleep complaints. Major sleep alterations in the postoperative period include sleep fragmentation, reduced total sleep time, and loss of time spent in slow wave and rapid eye movement sleep. Clinical and experimental studies show that sleep disturbances may exacerbate pain, whereas pain and opioid treatments disturb sleep. Surgical stress appears to be a major contributor to both sleep disruptions and altered pain perception. However, pain and the use of opioid analgesics could worsen sleep alterations, whereas sleep disruptions may contribute to intensify pain. Nevertheless, little is known about the relationship between postoperative sleep and pain. Although the sleep-pain interaction has been addressed from both ends, this review focuses on the impact of sleep disruptions on pain perception. A better understanding of the effect of postoperative sleep disruptions on pain perception would help in selecting patients at risk for more severe pain and may facilitate the development of more effective and safer pain management programs.